Vital-signs patch having a strain relief

ABSTRACT

A vital-signs monitor patch containing at least two electrodes, a circuit assembly, and a patch body having a chamber in which the circuit assembly is housed. The patch body also contains at least one flexible portion adjacent to the circuit assembly chamber, with at least one electrode attached to the flexible portion. The electrodes are configured for attaching the patch to the skin of a patient.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims the benefit of priority under 35 U.S.C.§120 as a divisional of U.S. patent application Ser. No. 12/844,774entitled “Vital-Signs Patch Having a Strain Relief,” and filed on Jul.27, 2010, the disclosure of which is hereby incorporated by reference inits entirety for all purposes. The following applications disclosecertain common subject matter with the present application: “AVital-Signs Monitor with Encapsulation Arrangement,” Attorney Docket No.080624-0612; “A Vital-Signs Monitor with Spaced Electrodes,” AttorneyDocket No. 080624-0623; “A Vital-Signs Patch Having a Strain Relief,”Attorney Docket No. 080624-0624; “A Temperature Probe Suitable forAxillary Reading,” Attorney Docket No. 080624-0781; “System and Methodfor Monitoring Body Temperature of a Person,” Attorney Docket No.080624-0782; “System and Method for Saving Battery Power in a VitalSigns Monitor,” Attorney Docket No. 080624-0628; “A System and Methodfor Conserving Battery Power in a Patient Monitoring System,” AttorneyDocket No. 080624-0629; “A System and Method for Saving Battery Power ina Patient Monitoring System,” Attorney Docket No. 080624-0630; “A SystemAnd Method for Tracking Vital-Signs Monitor Patches,” Attorney DocketNo. 080624-0783; “A System And Method for Reducing False AlarmsAssociated with Vital-Signs Monitoring,” Attorney Docket No.080624-0785; “A System And Method for Location Tracking of Patients in aVital-Signs Monitoring System,” Attorney Docket No. 080624-0784; “ASystem And Method for Reducing False Alarms Based on Motion and LocationSensing,” Attorney Docket No. 080624-0786; all of the listedapplications filed on Jul. 27, 2010.

BACKGROUND

Field

The present disclosure generally relates to systems and methods ofphysiological monitoring, and, in particular, relates to monitoring ofvital signs of patients.

Description of the Related Art

Some of the most basic indicators of a person's health are thosephysiological measurements that reflect basic body functions and arecommonly referred to as a person's “vital signs.” The four measurementscommonly considered to be vital signs are body temperature, pulse rate,blood pressure, and respiratory rate. Some clinicians consider oxygensaturation (S₀₂) to be a “fifth vital sign” particularly for pediatricor geriatric cases. Some or all of these measurements may be performedroutinely upon a patient when they arrive at a healthcare facility,whether it is a routine visit to their doctor or arrival at an EmergencyRoom (ER).

Vital signs are frequently taken by a nurse using basic tools includinga thermometer to measure body temperature, a sphygmomanometer to measureblood pressure, and a watch to count the number of breaths or the numberof heart beats in a defined period of time which is then converted to a“per minute” rate. If a patient's pulse is weak, it may not be possibleto detect a pulse by hand and the nurse may use a stethoscope to amplifythe sound of the patient's heart beat so that she can count the beats.Oxygen saturation of the blood is most easily measured with a pulseoximeter.

When a patient is admitted to a hospital, it is common for vital signsto be measured and recorded at regular intervals during the patient'sstay to monitor their condition. A typical interval is 4 hours, whichleads to the undesirable requirement for a nurse to awaken a patient inthe middle of the night to take vital sign measurements.

When a patient is admitted to an ER, it is common for a nurse to do a“triage” assessment of the patient's condition that will determine howquickly the patient receives treatment. During busy times in an ER, apatient who does not appear to have a life-threatening injury may waitfor hours until more-serious cases have been treated. While the patientmay be reassessed at intervals while awaiting treatment, the patient maynot be under observation between these reassessments.

Measuring certain vital signs is normally intrusive at best anddifficult to do on a continuous basis. Measurement of body temperature,for example, is commonly done by placing an oral thermometer under thetongue or placing an infrared thermometer in the ear canal such that thetympanic membrane, which shared blood circulation with the brain, is inthe sensor's field of view. Another method of taking a body temperatureis by placing a thermometer under the arm, referred to as an “axillary”measurement as axilla is the Latin word for armpit. Skin temperature canbe measured using a stick-on strip that may contain panels that changecolor to indicate the temperature of the skin below the strip.

Measurement of respiration is easy for a nurse to do, but relativelycomplicated for equipment to achieve. A method of automaticallymeasuring respiration is to encircle the upper torso with a flexibleband that can detect the physical expansion of the rib cage when apatient inhales. An alternate technique is to measure a high-frequencyelectrical impedance between two electrodes placed on the torso anddetect the change in impedance created when the lungs fill with air. Theelectrodes are typically placed on opposite sides of one or both lungs,resulting in placement on the front and back or on the left and rightsides of the torso, commonly done with adhesive electrodes connected bywires or by using a torso band with multiple electrodes in the strap.

Measurement of pulse is also relatively easy for a nurse to do andintrusive for equipment to achieve. A common automatic method ofmeasuring a pulse is to use an electrocardiograph (ECG or EKG) to detectthe electrical activity of the heart. An EKG machine may use 12electrodes placed at defined points on the body to detect varioussignals associated with the heart function. Another common piece ofequipment is simply called a “heart rate monitor.” Widely sold for usein exercise and training, heart rate monitors commonly consist of atorso band, in which are embedded two electrodes held against the skinand a small electronics package. Such heart rate monitors cancommunicate wirelessly to other equipment such as a small device that isworn like a wristwatch and that can transfer data wirelessly to a PC.

Nurses are expected to provide complete care to an assigned number ofpatients. The workload of a typical nurse is increasing, driven by acombination of a continuing shortage of nurses, an increase in thenumber of formal procedures that must be followed, and an expectation ofincreased documentation. Replacing the manual measurement and logging ofvital signs with a system that measures and records vital signs wouldenable a nurse to spend more time on other activities and avoid thepotential for error that is inherent in any manual procedure.

SUMMARY

For some or all of the reasons listed above, there is a need to be ableto continuously monitor patients in different settings. In addition, itis desirable for this monitoring to be done with limited interferencewith a patient's mobility or interfering with their other activities.

Embodiments of the patient monitoring system disclosed herein measurecertain vital signs of a patient, which include respiratory rate, pulserate, blood pressure, body temperature, and, in some cases, oxygensaturation (S_(O2)), on a regular basis and compare these measurementsto defined limits.

In certain aspects of the present disclosure, a vital-signs patch isprovided that includes at least two electrodes and a circuit assemblythat periodically take at least one measurement from the electrodes. Thepatch is a unitized device that contains the circuit assembly with theelectrodes on the underside of the patch. The patch can be attached to apatient with the electrodes in electrical contact with the patient'sskin. The segments of the patch that connect the electrodes to thecircuit assembly are flexible, which reduces the noise induced in themeasurement by stress on the contact between the electrodes and thepatient.

In certain aspects of the present disclosure, a vital-signs patch isprovided that includes a patch housing having a circuit housing portionand at least one flexible electrode portion, a circuit assembly, and atleast one electrode. The electrode is attached to the electrode portionof the patch housing and configured for attaching the patch housing tothe skin of the patient.

It is understood that other configurations of the subject technologywill become readily apparent to those skilled in the art from thefollowing detailed description, wherein various configurations of thesubject technology are shown and described by way of illustration. Aswill be realized, the subject technology is capable of other anddifferent configurations and its several details are capable ofmodification in various other respects, all without departing from thescope of the subject technology. Accordingly, the drawings and detaileddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding and are incorporated in and constitute a part of thisspecification, illustrate disclosed embodiments and together with thedescription serve to explain the principles of the disclosedembodiments. In the drawings:

FIG. 1 is a diagram illustrating an exemplary embodiment of a patientmonitoring system according to certain aspects of the presentdisclosure.

FIG. 2A is a perspective view of the vital-signs monitor patch of FIG. 1according to certain aspects of the present disclosure.

FIG. 2B is a cross-section of the vital-signs monitor patch of FIG. 1according to certain aspects of the present disclosure.

FIG. 2C is a functional block diagram illustrating exemplary electronicand sensor components of the vital-signs monitor patch of FIG. 1according to certain aspects of the present disclosure.

FIG. 3A is a perspective view of an exemplary embodiment of a patientmonitoring system according to certain aspects of the presentdisclosure.

FIGS. 3B, 3C, and 3D are side views of the embodiment of FIG. 3A invarious displaced configurations.

FIG. 4A is a perspective view of another embodiment of a patientmonitoring system according to certain aspects of the presentdisclosure.

FIGS. 4B, 4C, and 4D are side views of the embodiment of FIG. 4A invarious displaced configurations.

FIGS. 5A and 5B are perspective views of additional embodiments of apatient monitoring system according to certain aspects of the presentdisclosure.

DETAILED DESCRIPTION

Periodic monitoring of patients in a hospital is desirable at least toensure that patients do not suffer an un-noticed sudden deterioration intheir condition or a secondary injury during their stay in the hospital.It is impractical to provide continuous monitoring by a clinician andcumbersome to connect sensors to a patient, which are then connected toa fixed monitoring instrument by wires. Furthermore, systems that soundan alarm when the measured value exceeds a threshold value may soundalarms so often and in situations that are not truly serious that suchalarms are ignored by clinicians.

Measuring vital signs is difficult to do on a continuous basis. Accuratemeasurement of cardiac pulse, for example, can be done using anelectrocardiograph (ECG or EKG) to detect the electrical activity of theheart. An EKG machine may use up to 12 electrodes placed at variouspoints on the body to detect various signals associated with the cardiacfunction. Another common piece of equipment is termed a “heart ratemonitor.” Widely sold for use in exercise and physical training, heartrate monitors may comprise a torso band in which are embedded twoelectrodes held against the skin and a small electronics package. Suchheart rate monitors can communicate wirelessly to other equipment suchas a small device that is worn like a wristwatch and that can transferdata wirelessly to a personal computer (PC).

Monitoring of patients that is referred to as “continuous” is frequentlyperiodic, in that measurements are taken at intervals. In many cases,the process to make a single measurement takes a certain amount of time,such that even back-to-back measurements produce values at an intervalequal to the time that it takes to make the measurement. For the purposeof vital sign measurement, a sequence of repeated measurements can beconsidered to be “continuous” when the vital sign is not likely tochange an amount that is of clinical significance within the intervalbetween measurements. For example, a measurement of blood pressure every10 minutes may be considered “continuous” if it is considered unlikelythat a patient's blood pressure can change by a clinically significantamount within 10 minutes. The interval appropriate for measurements tobe considered continuous may depend on a variety of factors includingthe type of injury or treatment and the patient's medical history.Compared to intervals of 4-8 hours for manual vital sign measurement ina hospital, measurement intervals of 30 minutes to several hours maystill be considered “continuous.”

Certain exemplary embodiments of the present disclosure include a systemthat comprises a vital-signs monitor patch that is attached to thepatient, and a bridge that communicates with monitor patches and linksthem to a central server that processes the data, where the server cansend data and alarms to a hospital system according to algorithms andprotocols defined by the hospital.

The construction of the vital-signs monitor patch is described accordingto certain aspects of the present disclosure. As the patch may be worncontinuously for a period of time that may be several days, as isdescribed in the following disclosure, it is desirable to encapsulatethe components of the patch such that the patient can bathe or showerand engage in their normal activities without degradation of the patchfunction. An exemplary configuration of the construction of the patch toprovide a hermetically sealed enclosure about the electronics isdisclosed.

In the following detailed description, numerous specific details are setforth to provide a full understanding of the present disclosure. It willbe apparent, however, to one ordinarily skilled in the art thatembodiments of the present disclosure may be practiced without some ofthe specific details. In other instances, well-known structures andtechniques have not been shown in detail so as not to obscure thedisclosure.

FIG. 1 discloses a vital sign monitoring system according to certainembodiments of the present disclosure. The vital sign monitoring system12 includes vital-signs monitor patch 20, bridge 40, and surveillanceserver 60 that can send messages or interact with peripheral devicesexemplified by mobile device 90 and workstation 100.

Monitor patch 20 resembles a large adhesive bandage and is applied to apatient 10 when in use. It is preferable to apply the monitor patch 20to the upper chest of the patient 10 although other locations may beappropriate in some circumstances. Monitor patch 20 incorporates one ormore electrodes (not shown) that are in contact with the skin of patient10 to measure vital signs such as cardiac pulse rate and respirationrate. Monitor patch 20 also may include other sensors such as anaccelerometer, temperature sensor, or oxygen saturation sensor tomeasure other characteristics associated with the patient. These othersensors may be internal to the monitor patch 20 or external sensors thatare operably connected to the monitor patch 20 via a cable or wirelessconnection. Monitor patch 20 also includes a wireless transmitter thatcan both transmit and receive signals. This transmitter is preferably ashort-range, low-power radio frequency (RF) device operating in one ofthe unlicensed radio bands. One band in the United States (US) is, forexample, centered at 915 MHz and designated for industrial, scientificand medical (ISM) purposes. An example of an equivalent band in theEuropean Union (EU) is centered at 868 MHz. Other frequencies ofoperation may be possible dependent upon the InternationalTelecommunication Union (ITU), local regulations and interference fromother wireless devices.

Surveillance server 60 may be a standard computer server connected tothe hospital communication network and preferably located in thehospital data center or computer room, although other locations may beemployed. The server 60 stores and processes signals related to theoperation of the patient monitoring system 12 disclosed herein includingthe association of individual monitor patches 20 with patients 10 andmeasurement signals received from multiple monitor patches 20. Hence,although only a single patient 10 and monitor patch 20 are depicted inFIG. 1, the server 60 is able to monitor the monitor patches 20 formultiple patients 10.

Bridge 40 is a device that connects, or “bridges”, between monitor patch20 and server 60. Bridge 40 communicates with monitor patch 20 overcommunication link 30 operating, in these exemplary embodiments, atapproximately 915 MHz and at a power level that enables communicationlink 30 to function up to a distance of approximately 10 meters. It ispreferable to place a bridge 40 in each room and at regular intervalsalong hallways of the healthcare facility where it is desired to providethe ability to communicate with monitor patches 20. Bridge 40 also isable to communicate with server 60 over network link 50 using any of avariety of computer communication systems including hardwired andwireless Ethernet using protocols such as 802.11a/b/g or 802.3af. As thecommunication protocols of communication link 30 and network link 50 maybe very different, bridge 40 provides data buffering and protocolconversion to enable bidirectional signal transmission between monitorpatch 20 and server 60.

While the embodiments illustrated by FIG. 1 employ a bridge 20 toprovide communication link between the monitor patch 20 and the server60, in certain alternative embodiments, the monitor patch 20 may engagein direct wireless communication with the server 60. In such alternativeembodiments, the server 60 itself or a wireless modem connected to theserver 60 may include a wireless communication system to receive datafrom the monitor patch 20.

In use, a monitor patch 20 is applied to a patient 10 by a clinicianwhen it is desirable to continuously monitor basic vital signs ofpatient 10 while patient 10 is, in this embodiment, in a hospital.Monitor patch 20 is intended to remain attached to patient 10 for anextended period of time, for example, up to 5 days in certainembodiments, limited by the battery life of monitor patch 20. In someembodiments, monitor patch 20 is disposable when removed from patient10.

Server 60 executes analytical protocols on the measurement data that itreceives from monitor patch 20 and provides this information toclinicians through external workstations 100, preferably personalcomputers (PCs), laptops, or smart phones, over the hospital network 70.Server 60 may also send messages to mobile devices 90, such as cellphones or pagers, over a mobile device link 80 if a measurement signalexceeds specified parameters. Mobile device link 80 may include thehospital network 70 and internal or external wireless communicationsystems that are capable of sending messages that can be received bymobile devices 90.

FIG. 2A is a perspective view of the vital-signs monitor patch 20 shownin FIG. 1 according to certain aspects of the present disclosure. In theillustrated embodiment, the monitor patch 20 includes component carrier23 comprising a central segment 21 and side segments 22 on opposingsides of the central segment 21. In certain embodiments, the centralsegment 21 is substantially rigid and includes a circuit assembly (24,FIG. 2B) having electronic components and battery mounted to a rigidprinted circuit board (PCB). The side segments 22 are flexible andinclude a flexible conductive circuit (26, FIG. 2B) that connect thecircuit assembly 24 to electrodes 28 disposed at each end of the monitorpatch 20, with side segment 22 on the right shown as being bent upwardsfor purposes of illustration to make one of the electrodes 28 visible inthis view.

FIG. 2B is a cross-sectional view of the vital-signs patch 20 shown inFIGS. 1 and 2A according to certain aspects of the present disclosure.The circuit assembly 24 and flexible conductive circuit 26 describedabove can be seen herein. The flexible conductive circuit 26 operablyconnects the circuit assembly 24 to the electrodes 28. Top and bottomlayers 23 and 27 form a housing 25 that encapsulate circuit assembly 28to provide a water and particulate barrier as well as mechanicalprotection. There are sealing areas on layers 23 and 27 that encirclescircuit assembly 28 and is visible in the cross-section view of FIG. 2Bas areas 29. Layers 23 and 27 are sealed to each other in this area toform a substantially hermetic seal. Within the context of certainaspects of the present disclosure, the term ‘hermetic’ implies that therate of transmission of moisture through the seal is substantially thesame as through the material of the layers that are sealed to eachother, and further implies that the size of particulates that can passthrough the seal are below the size that can have a significant effecton circuit assembly 24. Flexible conductive circuit 26 passes throughportions of sealing areas 29 and the seal between layers 23 and 27 ismaintained by sealing of layers 23 and 27 to flexible circuit assembly28. The layers 23 and 27 are thin and flexible, as is the flexibleconductive circuit 26, allowing the side segment 22 of the monitor patch20 between the electrodes 28 and the circuit assembly 24 to bend asshown in FIG. 2A.

FIG. 2C is a functional block diagram 200 illustrating exemplaryelectronic and sensor components of the monitor patch 20 of FIG. 1according to certain aspects of the present disclosure. The blockdiagram 200 shows a processing and sensor interface module 201 andexternal sensors 232, 234 connected to the module 201. In theillustrated example, the module 201 includes a processor 202, a wirelesstransceiver 207 having a receiver 206 and a transmitter 209, a memory210, a first sensor interface 212, a second sensor interface 214, athird sensor interface 216, and an internal sensor 236 connected to thethird sensor interface 216. The first and second sensor interfaces 212and 214 are connected to the first and second external sensors 232, 234via first and second connection ports 222, 224, respectively. In certainembodiments, some or all of the aforementioned components of the module201 and other components are mounted on a PCB.

Each of the sensor interfaces 212, 214, 216 can include one or moreelectronic components that are configured to generate an excitationsignal or provide DC power for the sensor that the interface isconnected to and/or to condition and digitize a sensor signal from thesensor. For example, the sensor interface can include a signal generatorfor generating an excitation signal or a voltage regulator for providingpower to the sensor. The sensor interface can further include anamplifier for amplifying a sensor signal from the sensor and ananalog-to-digital converter for digitizing the amplified sensor signal.The sensor interface can further include a filter (e.g., a low-pass orbandpass filter) for filtering out spurious noises (e.g., a 60 Hz noisepickup).

The processor 202 is configured to send and receive data (e.g.,digitized signal or control data) to and from the sensor interfaces 212,214, 216 via a bus 204, which can be one or more wire traces on the PCB.Although a bus communication topology is used in this embodiment, someor all communication between discrete components can also be implementedas direct links without departing from the scope of the presentdisclosure. For example, the processor 202 may send data representativeof an excitation signal to the sensor excitation signal generator insidethe sensor interface and receive data representative of the sensorsignal from the sensor interface, over either a bus or direct data linksbetween processor 202 and each of sensor interface 212, 214, and 216.

The processor 202 is also capable of communication with the receiver 206and the transmitter 209 of the wireless transceiver 207 via the bus 204.For example, the processor 202 using the transmitter and receiver 209,206 can transmit and receive data to and from the bridge 40. In certainembodiments, the transmitter 209 includes one or more of a RF signalgenerator (e.g., an oscillator), a modulator (a mixer), and atransmitting antenna; and the receiver 206 includes a demodulator (amixer) and a receiving antenna which may or may not be the same as thetransmitting antenna. In some embodiments, the transmitter 209 mayinclude a digital-to-analog converter configured to receive data fromthe processor 202 and to generate a base signal; and/or the receiver 206may include an analog-to-digital converter configured to digitize ademodulated base signal and output a stream of digitized data to theprocessor 202. In other embodiments, the radio may comprise a directsequence radio, a software-defined radio, or an impulse spread spectrumradio.

The processor 202 may include a general-purpose processor or aspecific-purpose processor for executing instructions and may furtherinclude a memory 219, such as a volatile or non-volatile memory, forstoring data and/or instructions for software programs. Theinstructions, which may be stored in a memory 219 and/or 210, may beexecuted by the processor 202 to control and manage the wirelesstransceiver 207, the sensor interfaces 212, 214, 216, as well as provideother communication and processing functions.

The processor 202 may be a general-purpose microprocessor, amicrocontroller, a Digital Signal Processor (DSP), an ApplicationSpecific Integrated Circuit (ASIC), a Field Programmable Gate Array(FPGA), a Programmable Logic Device (PLD), a controller, a statemachine, gated logic, discrete hardware components, or any othersuitable device or a combination of devices that can performcalculations or other manipulations of information.

Information, such as program instructions, data representative of sensorreadings, preset alarm conditions, threshold limits, may be stored in acomputer or processor readable medium such as a memory internal to theprocessor 202 (e.g., the memory 219) or a memory external to theprocessor 202 (e.g., the memory 210), such as a Random Access Memory(RAM), a flash memory, a Read Only Memory (ROM), a ProgrammableRead-Only Memory (PROM), an Erasable PROM (EPROM), registers, a harddisk, a removable disk, or any other suitable storage device.

In certain embodiments, the internal sensor 236 can be one or moresensors configured to measure certain properties of the processing andsensor interface module 201, such as a board temperature sensorthermally coupled to a PCB. In other embodiments, the internal sensor236 can be one or more sensors configured to measure certain propertiesof the patient 10, such as a motion sensor (e.g., an accelerometer) formeasuring the patient's motion or position with respect to gravity.

The external sensors 232, 234 can include sensors and sensingarrangements that are configured to produce a signal representative ofone or more vital signs of the patient to which the monitor patch 20 isattached. For example, the first external sensor 232 can be a set ofsensing electrodes that are affixed to an exterior surface of themonitor patch 20 and configured to be in contact with the patient formeasuring the patient's respiratory rate, and the second external sensor234 can include a temperature sensing element (e.g., a thermocouple or athermistor or resistive thermal device (RTD)) affixed, either directlyor via an interposing layer, to skin of the patient 10 for measuring thepatient's body temperature. In other embodiments, one or more of theexternal sensors 232, 234 or one or more additional external sensors canmeasure other vital signs of the patient, such as blood pressure, pulserate, or oxygen saturation.

FIG. 3A is a perspective view of an exemplary embodiment of a patientmonitoring system according to certain aspects of the subjectdisclosure. The unitized patch 300 has a central section 305 thatcontains the electronics of the patch. Electrodes 320 are shown attachedto flaps 315 on opposite sides of section 305.

FIG. 3B is a side view of patch 300 of FIG. 3A in a configuration inwhich it is attached to a patient's body 301. Electrodes 320 are adheredto the patient's skin 302 and are coupled to flaps 315 of patch 300 by asnap fitting 330 that is electrically conductive and disconnectable. Thecentral section 305 is rigid, in these embodiments, as the circuitassembly incorporates a rigid printed circuit board (PCB). Flaps 315have segments 310 that are flexible between the snap fitting 330 and thecentral section 305. Each electrode 330 comprises a layer of adhesive325 on the surface that is in contact with the patient's skin 302.

One definition of ‘flexible’ is “capable of bending easily withoutbreaking.” The term ‘flexible’ is applied to various degrees of thiscapability to bend without breaking. Items that are sometimes describedas ‘flexible’ include a thin sheet of rubber, which can be foldedtightly upon itself without breaking, and a thin cantilevered steel rod,which will bend a perceptible amount when a transverse load is appliedat its tip and return to its original position when the load is removed.In the context of the disclosed vital-signs monitor patch 20, thesegments 310 of the patch 20 that are considered flexible are able to bebent by hand with very little effort into shapes that have one or morecurves. The flexible patch segments 310 need not be bendable into sharpcorners or folded flat against themselves. In the configuration where acompressive force is applied in the plane of the flexible segment 310 ofthe patch 20, the segment 310 will assume a wavy shape that is shorterin the direction of the applied force than prior to the application ofthe force, and the amount of force required to compress the segment 310a small amount, on the order of a few percent, is negligible. Thus,application of term ‘flexible’ to a segment 310 of the patch 20 that hasan electrode 320 attached at one end implies an ability of the patchsegment 310 to assume a shape with a reduced length with the loadapplied by the electrode 320 below the level that would create noiseartifacts.

It has been observed that the quality of the electrical connection ofelectrodes to a patient's body is strongly affected by mechanical stresson the connection between the electrode and the skin. This shows up asnoise artifacts in the measurement signal as the impedance of theconnection changes with stress on the connection. For example, the skinacross the chest contracts as a patient reaches forward with both hands.When this happens, a pair of rigidly connected electrodes that wereadhered to the chest of a patient while the patient's hands were attheir sides will experience significant shear force on each connectorwhen the patient reaches forward with both hands. The noise artifactsinduced in this situation in the signal from these electrodes arereferred to as “motion induced noise.” Even something as minor assitting up or walking around, both of which involve simple arm motions,are enough to produce significant noise in the measurement ofrespiration or pulse.

FIGS. 3C and 3D show displaced configurations of patch 300 when thepatient 10 bends or moves such that the portion of the patient's body301 under patch 300 is no longer of the same shape as it was when thepatch was initially applied, as would be typified by the configurationof FIG. 3B. In FIG. 3C, the patient is pulling on something such thatthe chest muscles 303 are contracting and the distance between theadhered electrodes 320 is reduced. As the electrodes 320 move towardseach other, the flexible segments 310 will bend and deform toaccommodate this motion. As a result, there is very little shear stressplaced on the adhesive 325 of electrodes 320. FIG. 3D shows a similarconfiguration where the patient 330 has bent over or moved such that thearea under the patch 300 is now curved. The flexible segments 310 havechanged shape to accommodate the motion and avoid applying stress to theadhesive 325 of electrodes 320. In addition, the swivel capability ofconnectors 330 permits rotary motion of the patch flaps 315 relative tothe electrodes 320 and avoided tension and compression stresses on theadhesive 325.

The disclosed embodiments of patch 300 provide a significant reductionin noise in the measurements of vital signs as the patient moves aboutduring normal activities. As an advantage of a vital-signs monitor 20 isits continuous monitoring during normal activity, reduced motion-inducednoise artifacts enables electrodes 320 to be closer together, whichfurther enables the entire patch 20 to be smaller and less intrusive inthe patient's activities.

The flexible connection between the electrodes 320 and the circuitassembly package 305 can be accomplished in a variety of configurationswithout departing from the scope of the present disclosure. FIG. 4Ashows an alternate embodiment of patch 350, wherein the electrodes 355are configured such that the surface of the electrode 355 isapproximately flush with the surface of the patch body. This could beimplemented as either a coating or film applied to the surface of thepatch body or an electrode embedded in the material of the body. In thisembodiment, conductive adhesive 360 is applied around electrode 355allowing a conductive gel (not shown) to be utilized between electrode355 and the skin 302 to improve electrical contact. The patch 20 hasflexible segments 310 between the central section 305 and the electrodes355. FIGS. 4C and 4D illustrate the behavior of the flexible segments310 in accommodating movement of the patient 10 without inducing stressin the adhesive 360 of the path so as to avoid inducing noise artifactsin the signal.

FIGS. 5A and 5B illustrate additional configurations of a vital-signspatch that are within the scope of the claims. Patch 500 of FIG. 5Ashows the two electrodes 320 positioned on a common side of centralsection 305. Adhesive (not shown) may be applied to the underside ofcentral section 305 to provide mechanical attachment to the patient.FIG. 5B shows patch 550 where the electrodes 320 are on opposite sidesof central section 305 in one direction and on a common side of centralsection 305 in the perpendicular direction. Patch 500 and 550 may besuitable for use in specific care situations or in conjunction withcertain medical procedures.

It can be seen that the disclosed embodiments of the vital-signs monitorpatch provide a mobile solution to monitoring the vital signs of apatient. The design of the vital-signs monitor patch frees nurses, orother caregivers, from the task of repetitively measuring the vitalsigns of their patients, allowing the caregivers to spend more time onother duties. The ability to continuously monitor a patient's vitalsigns using a monitor patch, together with the rest of the patientmonitoring system, increases the ability of the nurse to respond quicklyto a sudden change in a patient's condition, resulting in improved carefor the patient.

The strain relief capability of the patch body in the area between theelectrodes reduces the magnitude of noise-induced noise artifacts in themeasurement signals taken by the vital-signs monitoring patch. As noiseis one of the limiting factors in reducing the size of the monitorpatch, a lower level of noise enables the patch to be smaller. A smallerpatch is less intrusive to the patient and easier for the nurse or othercaregiver to apply.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. While theforegoing has described what are considered to be the best mode and/orother examples, it is understood that various modifications to theseaspects will be readily apparent to those skilled in the art, and thegeneric principles defined herein may be applied to other aspects. Thus,the claims are not intended to be limited to the aspects shown herein,but is to be accorded the full scope consistent with the languageclaims, wherein reference to an element in the singular is not intendedto mean “one and only one” unless specifically so stated, but rather“one or more.” Unless specifically stated otherwise, the term “some”refers to one or more. Pronouns in the masculine (e.g., his) include thefeminine and neuter gender (e.g., her and its) and vice versa. Headingsand subheadings, if any, are used for convenience only and do not limitthe invention.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Some of the stepsmay be performed simultaneously. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

Terms such as “top,” “bottom,” “front,” “rear” and the like as used inthis disclosure should be understood as referring to an arbitrary frameof reference, rather than to the ordinary gravitational frame ofreference. Thus, a top surface, a bottom surface, a front surface, and arear surface may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference.

A phrase such as an “aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations. Aphrase such as an aspect may refer to one or more aspects and viceversa. A phrase such as an “embodiment” does not imply that suchembodiment is essential to the subject technology or that suchembodiment applies to all configurations of the subject technology. Adisclosure relating to an embodiment may apply to all embodiments, orone or more embodiments. A phrase such an embodiment may refer to one ormore embodiments and vice versa.

The word “exemplary” is used herein to mean “serving as an example orillustration.” Any aspect or design described herein as “exemplary” isnot necessarily to be construed as preferred or advantageous over otheraspects or designs.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. §112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.” Furthermore, to the extent that the term “include,” “have,” or thelike is used in the description or the claims, such term is intended tobe inclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

What is claimed is:
 1. A vital-signs monitor patch, comprising: a rigidcentral portion that includes a circuit assembly configured to receiveand process vital-signs monitoring signals from first and secondelectrodes attached to skin of a patient; and first and second flexibleportions each extending from the central portion, wherein the firstflexible portion comprises a first portion of a first snap fitting thatextends from a surface of the first flexible portion and that isconfigured to rotatably attach to the first electrode, wherein thesecond flexible portion comprises a second portion of a second snapfitting that extends from a surface of the second flexible portion andthat is configured to rotatably attach to the second electrode, andwherein the first and second flexible portions are configured to allowthe rigid central portion to be movable with respect to the skin of thepatient when the first and second snap fittings are connected to thefirst and second electrodes and the first and second electrodes areattached to the skin of the patient.
 2. The vital-signs monitor patch ofclaim 1, wherein each electrode comprises a layer of adhesive that isconfigured to attach the electrode to the patient's skin.
 3. Thevital-signs monitor patch of claim 1, wherein the first portion of thefirst snap fitting is configured to rotatably attach to a second portionof the first snap fitting, the second portion of the first snap fittingdisposed on the first electrode.
 4. The vital-signs monitor patch ofclaim 3, wherein the first portion of the second snap fitting isconfigured to rotatably attach to a second portion of the second snapfitting, the second portion of the second snap fitting disposed on thesecond electrode.
 5. The vital-signs monitor patch of claim 1, whereinthe vital-signs monitoring signals correspond to at least one of atemperature, a pulse rate, a respiration rate, a blood pressure or anoxygen saturation.
 6. The vital-signs monitor patch of claim 1, whereinthe circuit assembly comprises a printed circuit board.
 7. Thevital-signs monitor patch of claim 6, wherein the circuit assemblyfurther comprises an internal sensor configured to measure a temperatureof the printed circuit board.
 8. A system comprising: a plurality ofvital-signs monitor patches, each patch comprising: a rigid centralportion that includes a circuit assembly configured to receive andprocess vital-signs monitoring signals from first and secondcorresponding electrodes attached to skin of a corresponding patient;and first and second flexible portions each extending from the centralportion, wherein the first flexible portion comprises a first portion ofa first snap fitting that extends from a surface of the first flexibleportion and that is configured to rotatably attach to the firstcorresponding electrode, wherein the second flexible portion comprises asecond portion of a second snap fitting that extends from a surface ofthe second flexible portion and that is configured to rotatably attachto the second corresponding electrode, and wherein the first and secondflexible portions are configured to allow the rigid central portion tobe movable with respect to the skin of the corresponding patient whenthe first and second snap fittings are connected to the first and secondcorresponding electrodes and the first and second correspondingelectrodes are attached to the skin of the corresponding patient; and aserver configured to receive and process measurement signals from thecircuit assembly of each of the patches for each corresponding patient.9. The system of claim 8, wherein the server is further configured tosend a message to a mobile device if one or more of the measurementsignals exceeds specified parameters.
 10. The system of claim 9, furthercomprises a bridge configured to facilitate wireless communicationsbetween at least one of the patches and the server.
 11. The system ofclaim 10, wherein the bridge is configured to facilitate the wirelesscommunications by performing data buffering and protocol conversion thatenables bidirectional signal transmission between the at least one ofthe patches and the server.
 12. The system of claim 8, wherein, for eachpatch, the first portion of the first snap fitting is configured torotatably attach to a second portion of the first snap fitting, thesecond portion of the first snap fitting disposed on the firstcorresponding electrode.
 13. The system of claim 12, wherein the firstportion of the second snap fitting is configured to rotatably attach toa second portion of the second snap fitting, the second portion of thesecond snap fitting disposed on the second corresponding electrode. 14.The system of claim 8, wherein the vital-signs monitoring signalscorrespond to at least one of a temperature, a pulse rate, a respirationrate, a blood pressure or an oxygen saturation for the correspondingpatient.
 15. A vital-signs monitor patch, comprising: a rigid centralportion; a circuit assembly disposed in the rigid central portion,wherein the circuit assembly is configured to receive and processvital-signs monitoring signals from first and second electrodes; a firstflexible portion extending from a first side of the central portion; afirst snap fitting extending from a surface of the first flexibleportion; a second flexible portion extending from a second side of thecentral portion; and a second snap fitting extending from a surface ofthe second flexible portion, wherein the first snap fitting isconfigured to rotatably attach to the first electrode, wherein thesecond snap fitting is configured to rotatably attach to the secondelectrode, and wherein the first and second flexible portions areconfigured to allow the rigid central portion to move relative to thefirst and second snap fittings.
 16. The vital-signs monitor patch ofclaim 15, wherein the first snap fitting is configured to rotatablyattach to a complementary snap feature on the first electrode.
 17. Thevital-signs monitor patch of claim 16, wherein the second snap fittingis configured to rotatably attach to a complementary snap feature on thesecond electrode.
 18. The vital-signs monitor patch of claim 15, whereinthe vital-signs monitoring signals correspond to at least one of atemperature, a pulse rate, a respiration rate, a blood pressure or anoxygen saturation.
 19. The vital-signs monitor patch of claim 15,wherein the circuit assembly comprises a printed circuit board.
 20. Thevital-signs monitor patch of claim 19, wherein the circuit assemblyfurther comprises an internal sensor on the printed circuit board andconfigured to monitor the circuit assembly.